view src/os/unix/ngx_process_cycle.h @ 8018:5119c8150478

Fixed runtime handling of systems without EPOLLRDHUP support. In 7583:efd71d49bde0 (nginx 1.17.5) along with introduction of the ioctl(FIONREAD) support proper handling of systems without EPOLLRDHUP support in the kernel (but with EPOLLRDHUP in headers) was broken. Before the change, rev->available was never set to 0 unless ngx_use_epoll_rdhup was also set (that is, runtime test for EPOLLRDHUP introduced in 6536:f7849bfb6d21 succeeded). After the change, rev->available might reach 0 on systems without runtime EPOLLRDHUP support, stopping further reading in ngx_readv_chain() and ngx_unix_recv(). And, if EOF happened to be already reported along with the last event, it is not reported again by epoll_wait(), leading to connection hangs and timeouts on such systems. This affects Linux kernels before 2.6.17 if nginx was compiled with newer headers, and, more importantly, emulation layers, such as DigitalOcean's App Platform's / gVisor's epoll emulation layer. Fix is to explicitly check ngx_use_epoll_rdhup before the corresponding rev->pending_eof tests in ngx_readv_chain() and ngx_unix_recv().
author Marcus Ball <marcus.ball@live.com>
date Mon, 30 May 2022 02:38:07 +0300
parents b4cc553aafeb
children
line wrap: on
line source


/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_PROCESS_CYCLE_H_INCLUDED_
#define _NGX_PROCESS_CYCLE_H_INCLUDED_


#include <ngx_config.h>
#include <ngx_core.h>


#define NGX_CMD_OPEN_CHANNEL   1
#define NGX_CMD_CLOSE_CHANNEL  2
#define NGX_CMD_QUIT           3
#define NGX_CMD_TERMINATE      4
#define NGX_CMD_REOPEN         5


#define NGX_PROCESS_SINGLE     0
#define NGX_PROCESS_MASTER     1
#define NGX_PROCESS_SIGNALLER  2
#define NGX_PROCESS_WORKER     3
#define NGX_PROCESS_HELPER     4


typedef struct {
    ngx_event_handler_pt       handler;
    char                      *name;
    ngx_msec_t                 delay;
} ngx_cache_manager_ctx_t;


void ngx_master_process_cycle(ngx_cycle_t *cycle);
void ngx_single_process_cycle(ngx_cycle_t *cycle);


extern ngx_uint_t      ngx_process;
extern ngx_uint_t      ngx_worker;
extern ngx_pid_t       ngx_pid;
extern ngx_pid_t       ngx_new_binary;
extern ngx_uint_t      ngx_inherited;
extern ngx_uint_t      ngx_daemonized;
extern ngx_uint_t      ngx_exiting;

extern sig_atomic_t    ngx_reap;
extern sig_atomic_t    ngx_sigio;
extern sig_atomic_t    ngx_sigalrm;
extern sig_atomic_t    ngx_quit;
extern sig_atomic_t    ngx_debug_quit;
extern sig_atomic_t    ngx_terminate;
extern sig_atomic_t    ngx_noaccept;
extern sig_atomic_t    ngx_reconfigure;
extern sig_atomic_t    ngx_reopen;
extern sig_atomic_t    ngx_change_binary;


#endif /* _NGX_PROCESS_CYCLE_H_INCLUDED_ */